The present invention relates to an electric machine.
Electric machines are generally known.
The known electrical machine has a housing. In the housing a rotor shaft is mounted in bearings such that it is capable of rotating about a shaft axis. The housing has two end faces and a lateral surface. The housing axially delimits a housing interior with the end faces. The housing radially delimits the housing interior with the lateral surface. A rotor laminate stack is arranged on the rotor shaft in a manner fixed against rotation. The rotor laminate stack has axially running cooling channels and radially running cooling channels. The radially running cooling channels of the rotor laminate stack are open radially outwards and extend radially inwards at least as far as the axially running cooling channels. The housing has two axial dividers, which extend radially inwards starting from the lateral surface, but end in front of the rotor shaft. The axial dividers are arranged between the rotor laminate stack and the end faces, when viewed in the axial direction. The housing has axial ribs, which are arranged so as to be distributed over the circumference of the lateral surface, run axially at least between the axial dividers and extend radially inwards. They bear a stator laminate stack. The stator laminate stack interacts electrically with the rotor laminate stack. The stator laminate stack has radially running cooling channels, which are open radially inwards and radially outwards and interact with the radially running cooling channels of the rotor laminate stack. The stator laminate stack bears a stator winding. The stator winding has end windings, which protrude axially on both sides out of the stator laminate stack. The axial dividers extend radially inwards to such an extent that they overlap the end windings, when viewed in the radial direction.
The lateral surface has, in a first tangential region, two inlet openings and an outlet opening for cooling air. The inlet openings are arranged between in each case one of the end faces and in each case one of the axial dividers, when viewed in the axial direction. The outlet opening is arranged between the axial dividers, when viewed in the axial direction.
In the electric machine from the prior art, the cooling air is introduced into the rotor laminate stack axially from both sides. The cooling air flows first through the rotor laminate stack and then through the stator laminate stack. The cooling air emerges radially outwards from the stator laminate stack. Then the cooling air either emerges on the outside directly via the outlet opening or flows axially into a region in which the end windings are arranged. There, the cooling air flows tangentially until it reaches the first tangential region. There, the cooling air flows through the outlet opening and emerges from the electric machine.
A second proportion of the cooling air does not flow through the rotor laminate stack but directly through the end windings. This proportion of the cooling air emerges directly radially outwards after flowing through the end windings and is mixed with the first proportion of cooling air. Sometimes, the first and second proportions of cooling air impede one another in this process.
It is known in the prior art to accept that the proportions of cooling air will impede one another in this way and to swallow the decreased utilization of the electric machine associated therewith. It is furthermore known to use relatively strong fans which bring about a correspondingly large cooling air flow. It is furthermore known to use completely different cooling air guides.